1. Field of the Invention
The present invention relates to a system and method for monitoring the departure of a person, such as an infant or mentally disturbed patient from a hospital, a child from a day-care center, or other vulnerable person from an area having an electronic article surveillance system.
2. Description of the Prior Art
Systems for monitoring the exit of infants from hospital maternity wards, or wandering elderly from care facilities are known. Also known are systems for monitoring inmates. Problems presented by the propensity of children to wander and become lost have been the subject of much investigation. Numerous devices have been disclosed over the years to tackle these problems. U.S. Pat. No. 5,848,567 to Colaianni discloses a leash adapted to attach a child to the guardian. U.S. Pat. No. 5,510,771 to Marshall employs a cable that alarms if it is broken. These devices put sever limitations on the mobility of child and guardian. U.S. Pat. No. 4,694,284 to Leveille et al. transmits an alarm signal when a collar is removed from a child. U.S. Pat. No. 5,617,074 to White discloses a button having a transmitter and adapted to be attached to a child""s clothing or wrist strap. The button actuates an alarm if it is tampered with. Such devices may help deter abduction, but provide a less than satisfactory solution to the problem presented by a wondering child.
Generally, electronic devices designed either to monitor children within an enclosed area, or within the framework of an individual system. In the first case, the system alarms when the child leaves the monitored area. In the second case, the child wears a tag and the guardian carries a control unit. When the child strays too far from the unit, the distance between the two causes the sounding of an alarm carried by either or both of the control unit and the tag.
U.S. Pat. No. 5,337,041 to Friedman employs a tag worn by a child and adapted to be triggered by the guardian to sound an alarm when the child is out of sight. U.S. Pat. No. 5,307,763 to Arthur et al. places a loop antenna around the border of an area appointed for confinement of a child and tag alarms adapted to be worn by a child when appointed for transport outside the protected area. This device is expensive, requiring purchase of a monitoring system and wiring of an entire monitored area. U.S. Pat. No. 5,640,147 to Chek et al. discloses a tag adapted to be worn by a child. The tag is provided with a microphone and transmitter, which enables a parent to listen in and thereby monitor the child""s activity. These devices may help deter abduction, but they fail to solve the problem presented by the wondering child.
Numerous devices are adapted to trigger an alarm when a battery-powered tag worn by the child exceeds a predetermined distance from a transmitter carried by the guardian. Representative of these devices are those disclosed by: DE Patent 19,608,348 to Whitehurst; U.S. Pat. No. 5,841,352 to Prakash, U.S. Pat. No. 5,661,460 to Budzyna et al.; WO Patent 9,618,913 to Budzyna et al.; WO Patent 9,627,173 to Campana; WO Patent 9,614,625 to Edwards; U.S. Pat. No. 5,512,879 to Stokes; WO Patent 9,607,998 to Gerstenberger et al.; GB Patent 2,279,170 to Newton; U.S. Pat. No. 5,289,163 to Perez et al.; GB Patent 2,248,331; U.S. Pat. No. 4,899,135 to Gharariiran; U.S. Pat. No. 5,557,259 to Musa; U.S. Pat. No. 5,461,365 to Baringer et al. FR 2704345 to Gadi; GB Patent 2,276,025 to Bartwell; FR Patent 2,674,351 to Dal Bo et al; FR Patent 2,608,868 to Estienne; WO Patent 8,706,748 to Corwin et al.; GB2182183 to Garrett et al.; U.S. Pat. No. 4,598,272 to Cox; FR Patent 2,543,715 to Mayer; DE Patent 3,215,942 to Fuchshuber; GB Patent 1,496,945; U.S. Pat. No. 5,6890240 to Traxler; and U.S. Pat. No. 5,812,056 to Law. Retail stores oftentimes generate large amounts of electronic noise. Such noise typically emanates from point of sale equipment and electronic article surveillance systems. Representative of these systems is the anti-pilferage tag system disclosed by U.S. Pat. No. 4,992,776 to Crossfield. These devices frequently exhibit extreme performance variability with differing electronic noise environments. U.S. Pat. No. 5,629,678 to Gargano et al. employs a tag that is implanted in the child; and which has obvious shortcomings. In each of these devices there is imposed an additional restriction that impedes the performance thereof. The additional restriction requires that the store install special monitoring equipment or that the guardian carry a monitoring unit.
Additional variations of a child monitoring system have been disclosed. British Patent 2,291,303 to Duffy provides direction to a transmitter worn by the child. In U.S. Pat. No. 4,785,291, the tone changes with distance changes. U.S. Pat. No. 5,119,072 to Hemingway discloses a weak signal alarm with a microphone. U.S. Pat. No. 5,021,794 to Lawrence uses transmitter/receiver and works through the cellular phone system. GB Patent 2,218,245 to Hoyle et al. discloses a device that protects babies from unauthorized removal from a hospital. GB Patent 2,248,330 to Seeman uses infrared or sonic signals. WO Patent 8,703,404 to Royoux has LEDS indicating direction and distance. In each of these devices there is imposed the further requirement that the store install special monitoring equipment or the guardian carry a monitoring unit.
EP Patent 323,041 to Newman et al. uses a magnetic strip in a wrist or ankle strap to protect against unauthorized removal of an infant. This is one of the technologies used in electronic article surveillance (EAS) systems. Numerous EAS patents exist that employ a magnetic strip. Representative of these EAS patents is U.S. Pat. No. 4,553,136 to Anderson, et al. Unfortunately, devices utilizing EAS technology have a very short detection range, typically three feet, and suffer from a low detection rate. Such systems are also susceptible to false alarms.
When EAS systems are used, markers are attached to articles, such as computers, to be protected. The markers are responsive to an electromagnetic field generated at the facility""s exit by the EAS system""s transmitter. Each marker must be removed or deactivated before an article to which it is affixed leaves the facility. Otherwise, upon exiting the facility, the marker disturbs the field. This disturbance is detected by the EAS system, and an alarm is triggered. U.S. Pat. No. 4,510,489 discloses a technology used in EAS systems that have been employed in retail stores to protect against shoplifting, office buildings to protect against equipment theft, hospitals to protect infants from unauthorized removal, and elderly care facilities to secure wandering patients. EAS markers are generally inexpensive and operate as a passive device, without their own power. As a result, the operating range of EAS markers is limited and their detection rate, though acceptable for some applications, is much too low to assure protection of people.
Implementation of a person monitoring system within a facility in the conventional way would require the facility to purchase and maintain a system. If the facility already possessed an EAS system, it would have to maintain both systems. This is a costly solution. The shear number of teachings directed to these monitoring systems and the conspicuous absence from the marketplace of systems for monitoring the departure of persons from facilities such as hospitals, retail sales establishments and the like, strongly suggests that the problem remains to be solved.
Accordingly, there remains a need in the art for a cost-effective system that exhibits an extremely high detection rate and which accurately and reliably monitors and protects against the unauthorized departure of persons from hospitals, stores, day care centers, bus and train stations, airports, office buildings and other facilities.
The present invention provides a system and method for monitoring the departure of a person from a facility or other area wherein an electronic article surveillance system has previously been installed or is appointed to be installed. The invention can be used to monitor day-care centers, juvenal detention centers and psychiatric facilities. It is especially suited for use in hospitals or care facilities to monitor the whereabouts of newborns, the elderly, or emotionally disturbed residents or patients. The invention provides protection for a broad range of vulnerable persons such as children, or having an infirmity, such as a mentally disturbed patient, an Alzheimer""s patient, and the like. Additionally, the invention can be used to monitor low risk inmates of detention centers. Dual alarm capability is preferably provided, by sounding of alarms at the exit and within the tag worn by the exiting person.
Many facilities currently have electronic article surveillance systems for protecting against equipment theft, and more buildings are employing them every year. The present invention is especially suited for and leverages the use of these electronic article surveillance systems by adding thereto person-monitoring functionality.
Generally stated, the present invention provides a tag for monitoring the departure of a vulnerable or at-risk person from an exit having an electronic article surveillance system, comprising an antenna means for receiving an electromagnetic field generated by the electronic article surveillance system, an alarm means for sounding an alarm, a detecting means for detecting the electromagnetic field, the detecting means causing the alarm means to sound an alarm upon detection of the electromagnetic field, a power means, for powering the tag, a housing means for encasing the antenna means, the detecting means, the alarm means, and the power means, and an attaching means for attaching the housing means to the person.
The tag further comprises a generating means for generating a signal mimicking an electronic article surveillance marker, and a switching means for switching the antenna between the detecting means and the generating means, whereby upon detection of the electromagnetic field, the detecting means causes the alarm means to sound an alarm and the switching means to connect the antenna to the generating means causing the electronic article surveillance system to alarm.
Still further, the invention provides a method for detecting the departure of a person from an exit provided with an electronic article surveillance system, comprising the steps of: (a) attaching a tag to the person, the tag being responsive to the electromagnetic field generated by the electronic article surveillance system at the exit; receiving the electromagnetic field; and sounding an alarm on the tag, the alarm being triggered by departure of the person from the exit. The method further comprises the step of sounding the alarm of the electronic article surveillance system upon departure from the exit of a person to which the tag is attached.
In another embodiment of the invention, the tag comprises: a first passive marker having an elongated axis; and a second passive marker having an elongated axis, where the elongated axis of the first passive marker is fixed in a position substantially perpendicular to the elongated axis of the second passive marker.
Advantageously, the present invention leverages a store""s preexisting EAS system by adding thereto a person monitoring functionality. Stores without EAS systems can obtain the benefits of the theft protection and person monitoring functions by employing this invention. In addition, the method and apparatus of the invention are much more cost effective, efficient, and reliable than devices wherein the person monitoring function is approached in the conventional way.